1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char rcsid[] = "$OpenBSD: fvwrite.c,v 1.12 2003/06/02 20:18:37 millert Exp $"; 35 #endif /* LIBC_SCCS and not lint */ 36 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <errno.h> 41 #include "local.h" 42 #include "fvwrite.h" 43 44 /* 45 * Write some memory regions. Return zero on success, EOF on error. 46 * 47 * This routine is large and unsightly, but most of the ugliness due 48 * to the three different kinds of output buffering is handled here. 49 */ 50 int 51 __sfvwrite(fp, uio) 52 register FILE *fp; 53 register struct __suio *uio; 54 { 55 register size_t len; 56 register char *p; 57 register struct __siov *iov; 58 register int w, s; 59 char *nl; 60 int nlknown, nldist; 61 62 if ((len = uio->uio_resid) == 0) 63 return (0); 64 /* make sure we can write */ 65 if (cantwrite(fp)) { 66 errno = EBADF; 67 return (EOF); 68 } 69 70 #define MIN(a, b) ((a) < (b) ? (a) : (b)) 71 #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n)) 72 73 iov = uio->uio_iov; 74 p = iov->iov_base; 75 len = iov->iov_len; 76 iov++; 77 #define GETIOV(extra_work) \ 78 while (len == 0) { \ 79 extra_work; \ 80 p = iov->iov_base; \ 81 len = iov->iov_len; \ 82 iov++; \ 83 } 84 if (fp->_flags & __SNBF) { 85 /* 86 * Unbuffered: write up to BUFSIZ bytes at a time. 87 */ 88 do { 89 GETIOV(;); 90 w = (*fp->_write)(fp->_cookie, p, MIN(len, BUFSIZ)); 91 if (w <= 0) 92 goto err; 93 p += w; 94 len -= w; 95 } while ((uio->uio_resid -= w) != 0); 96 } else if ((fp->_flags & __SLBF) == 0) { 97 /* 98 * Fully buffered: fill partially full buffer, if any, 99 * and then flush. If there is no partial buffer, write 100 * one _bf._size byte chunk directly (without copying). 101 * 102 * String output is a special case: write as many bytes 103 * as fit, but pretend we wrote everything. This makes 104 * snprintf() return the number of bytes needed, rather 105 * than the number used, and avoids its write function 106 * (so that the write function can be invalid). 107 */ 108 do { 109 GETIOV(;); 110 if ((fp->_flags & (__SALC | __SSTR)) == 111 (__SALC | __SSTR) && fp->_w < len) { 112 size_t blen = fp->_p - fp->_bf._base; 113 unsigned char *_base; 114 int _size; 115 116 /* Allocate space exponentially. */ 117 _size = fp->_bf._size; 118 do { 119 _size = (_size << 1) + 1; 120 } while (_size < blen + len); 121 _base = realloc(fp->_bf._base, _size + 1); 122 if (_base == NULL) 123 goto err; 124 fp->_w += _size - fp->_bf._size; 125 fp->_bf._base = _base; 126 fp->_bf._size = _size; 127 fp->_p = _base + blen; 128 } 129 w = fp->_w; 130 if (fp->_flags & __SSTR) { 131 if (len < w) 132 w = len; 133 COPY(w); /* copy MIN(fp->_w,len), */ 134 fp->_w -= w; 135 fp->_p += w; 136 w = len; /* but pretend copied all */ 137 } else if (fp->_p > fp->_bf._base && len > w) { 138 /* fill and flush */ 139 COPY(w); 140 /* fp->_w -= w; */ /* unneeded */ 141 fp->_p += w; 142 if (fflush(fp)) 143 goto err; 144 } else if (len >= (w = fp->_bf._size)) { 145 /* write directly */ 146 w = (*fp->_write)(fp->_cookie, p, w); 147 if (w <= 0) 148 goto err; 149 } else { 150 /* fill and done */ 151 w = len; 152 COPY(w); 153 fp->_w -= w; 154 fp->_p += w; 155 } 156 p += w; 157 len -= w; 158 } while ((uio->uio_resid -= w) != 0); 159 } else { 160 /* 161 * Line buffered: like fully buffered, but we 162 * must check for newlines. Compute the distance 163 * to the first newline (including the newline), 164 * or `infinity' if there is none, then pretend 165 * that the amount to write is MIN(len,nldist). 166 */ 167 nlknown = 0; 168 nldist = 0; /* XXX just to keep gcc happy */ 169 do { 170 GETIOV(nlknown = 0); 171 if (!nlknown) { 172 nl = memchr((void *)p, '\n', len); 173 nldist = nl ? nl + 1 - p : len + 1; 174 nlknown = 1; 175 } 176 s = MIN(len, nldist); 177 w = fp->_w + fp->_bf._size; 178 if (fp->_p > fp->_bf._base && s > w) { 179 COPY(w); 180 /* fp->_w -= w; */ 181 fp->_p += w; 182 if (fflush(fp)) 183 goto err; 184 } else if (s >= (w = fp->_bf._size)) { 185 w = (*fp->_write)(fp->_cookie, p, w); 186 if (w <= 0) 187 goto err; 188 } else { 189 w = s; 190 COPY(w); 191 fp->_w -= w; 192 fp->_p += w; 193 } 194 if ((nldist -= w) == 0) { 195 /* copied the newline: flush and forget */ 196 if (fflush(fp)) 197 goto err; 198 nlknown = 0; 199 } 200 p += w; 201 len -= w; 202 } while ((uio->uio_resid -= w) != 0); 203 } 204 return (0); 205 206 err: 207 fp->_flags |= __SERR; 208 return (EOF); 209 } 210